1. Field of the Invention
The invention relates to a mold, and in particular, to a feeding mold adapted for an in-mold roller (IMR).
2. Description of Related Art
Currently, many electronic devices, such as notebook computers, tablet PCs, or mobile phones, will add patterns or colors on the surface of a casing, so as to beautify the electronic device. Currently, methods of forming patterns or colors onto a surface of a casing includes methods such as spraying or printing. However, the surface treatment technology of spraying is complicated, and creates pollution. In addition, printing is limited to the chemical properties of the material, and is unable to create better external appearances.
In order to form a better pattern on a casing, a popular method is using an IMR. First, a film including a decorative pattern is disposed in a mold for injection molding. Next, resin is melted and filled in a side of the film, so that the melted resin is combined with the film to form a decorative film. Finally, the decorative film is extracted from the mold. Herein, the IMR process is complete.
However, as the thicknesses of casings gradually become thinner, in order to increase the strength and rigidity of casings, glass fibers are added into the plastic material. However, plastic material containing high glass fiber must be maintained under high temperature with good fluidity, so as to achieve a high gloss of the surface when injection molding. In addition, plastic material containing high glass fiber does not have the effects of bonding wires or floating fibers. Therefore, the injection molding requirements are strict (e.g. high injection speed), and so defects in the external appearance are easily created after the decorative film is combined with the casing.